Failure Analysis of Tubing Collapse in a Gas Well

Table 3

Mechanical properties of the failed tubing and the same batch of tubing without failure.

Sample	Tensile test			Charpy impact test
	Rm (MPa)	Rt0.7 (MPa)	A (%)	KV2 (J)
Failed pipe body	906	851	15	89, 97, 95
The tubing body in the same batch	833	791	22	117, 119, 116
Requirements of ordering technical agreement requirement	≥793	758–828	≥12	≥44 29≤ Only allow 1 value <44